Centrifugal switch.



J. A. VOLK, JR. i GENTRIPUGAL SWITCH.

APPLICATION FILED OCT. 11, 1911.

1,031,893, Patented July 9,1912.

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WITNESSES. l/Vl/EI'VTDR JW M M ATT RIVEY 2 0 JOSEPH A. VOLK, JR, OF SOUTH NORWALK, CONNECTICUT.

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Specification of Letters Patent.

Patented J uly9, 1912.

' Application filed October 11, 1911. No. 654,140.

To all whom it may concern:

Be it known that I, JOSEPH A. VoLK, J r., a citizen of the UnitedfStates residing at South Norwalk, county of Falrfield, State of Connecticut; have invented an Improvement in Centrifugal Switches, of which the following is a specification.

This invention has for its object to pro-- vide an automatic centrifugal switch adapted for general use wherever short circuiting is requlred, as for instance to stop a clock by electrical connections when a shaft stops or starts, and in starting an alternatim current motor and which is especially adapted for use upon motor cars using a storage battery and generator to'permit current to pass from the generator to the storage battery when the generator is running and to open the circuit and prevent exhaustion of the storage battery when the generator stops.

With these and other objects in View I have devised the novel centrifugal switch which I will now describe, referring to the accompanying drawing forming a part of this specification and using reference characters to indicate the several parts.

Figure 1 is a section of my novelswitch showing the brushes in place; Fig. 2 an elevation of the case with the cover plate removed; Fig. 3 an elevation of the cover plate detached; and Fig. 4 is an edge view of the switch as inuse. I

lO-denotes the shaft andll a casing made of any suitable insulating material, as fiber, which is rigidly secured thereto as by-a drive fit and is provided with 'a cover plate 12 secured in place by screws or in any suitable manner. The casing is provided with a circular recess 13 which is partly (less than half) filled with mercury, indicated by 14. Surrounding the periphery of the casing are two collector rings, indicated by 15 and 16. These rings fit closely and each ring is secured to the casing by a screw 17 which passes through the rlng and through the' peripheral wall of the casing and projects into the circular recess.

18 denotes brushes, ordinarily of copper, which are partly recessed in current-carry ing sockets 19 which are rigidly secured in place in any suitable manner. Springs 20 within the sockets act'to force the brushes forward and retain them in close engagement with the collector rings. 21 denotes current wires connected to the sockets.

The operation'is as follows: In Fig. 1, the

' within said casing,

shaft and easing are at rest and the mercury of course lies at the bottom of the recess as shown,'and current cannot pass from one collector ringto the other. As soon as the shaft and easing commence to rotate, however, centrifugal force will cause the mercury to line the inner peripheral wall of the recess and consequently to contact with both screws 17, thus establishing an electric connection between the two collector rings and through the brushesand sockets to the current wires, so that, for example, if used between a generator and a storage battery on a motor car, current will pass freely through the switch to the storage battery. Should the shaft and easing cease to rotate, however, the mercury will drop down into the bottom of therecess, as in .Fig. 1, and the circuit will be opened, this for the rea son that the quantity of mercu small enough so that it is impossible for but one of the screws 17 to contact cury when the shaft and easing are at rest, it being of course immaterial if the casing should stop in a position to leave both screws out of contact with the mercury.

Having thus described my invention I claim:

1. A switch of the character described comprising an insulating casing, mercury two collector rings on the periphery thereof and a screw passing through each ring and extending into the casin so that when the casing is rotated centrifugal force will cause the mercury to contact with each screw and establish electrical connection between the rings.

2. Av switch of the character described comprising an insulating casing, mercury within said casing, two collector rings on the periphery thereof and means for establishing electrical connect-ion between the rings through the mercury when the switch is rotated.

3. A switch of the character described comprisingan insulating casing, mercury within sald casing, two collector rings on the periphery thereof, a screw passing through each ring and extending into the casing and brushes engaging the rings.

4. A switch of the character described comprising an insulating casing having a hub for engaging a shaft and a circular recess, mercury within said recess, two collector rings on the periphery of the casing and a screw passing through each ring and exis always tendin into the casing, substantially as describe for the purpose specified.

5. A switch of the character described comprising an insulating casing having a circular recess, a quantity of mercury less than half filling said recess, two collector rings on the periphery of the casing and a screw passing through each ring and extending into the casing, so that when the 10 casing is rotated the mercury will contact with both screws and when the casing is stationary the mercury can contact with one screw only.

In testimony whereof I affix my signature in presence of two witnesses.

JOSEPH A. VOLK, JR.

Witnesses:

EDWARD B. SMITH, FRANK T. BRUNDAGE. 

